Image playback device and method and electronic camera with image playback function

ABSTRACT

An image playback device, which may be part of an electronic camera, reads out recorded information that has been recorded on a recording medium. A time period discriminator receives the recorded information read out by the image playback device and discriminates periods of time during which recorded information agrees with certain pre-set conditions. Moving-picture image information contained in the recorded information is played back and displayed in accordance with results of the discrimination.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Japanese Patent Application No.08-339338 filed Dec. 19, 1996, which is incorporated herein byreference.

This application is a continuation of application Ser. No. 09/965,858filed Oct. 1, 2001 (abandoned), which is a continuation of applicationSer. No. 08/993,984 filed Dec. 18, 1997 (abandoned).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention concerns an image playback device which plays backmoving-picture image information, and an electronic camera which has amoving-picture image information playback function. More specifically,the present invention concerns an image playback device and anelectronic camera which can select or discard moving-picture imageinformation according to prescribed set conditions, and which can playback and display such information only during certain limited periods.

2. Related Background Art

In the past, image playback devices and electronic cameras which playback moving-picture image information recorded on a recording mediumhave been adapted for practical use.

Especially in recent years, as a result of the development of digitalimage processing using computers, etc., devices which play back imagefiles that have been subjected to high-efficiency encoding such as theMPEG standard, etc., have become known.

In image playback devices of this type, when instructions are given forthe playback of a prescribed image file, the moving-picture imageinformation contained in the image file is played back and displayedthroughout a continuous time period.

However, unedited image files contain numerous unnecessary playbackimages (hereafter referred to as “unnecessary locations”). Ordinarily,the operator runs the playback images at fast forward in order to skipover such unnecessary locations.

During such fast-forward operation, the operator must confirm the endpoints of unnecessary locations visually, and must therefore constantlymonitor fast-forward images which have poor visual recognitioncharacteristics. As a result, fast-forward skipping of unnecessarylocations is tedious and difficult.

Furthermore, it often happens that the operator will not notice the endpoint of an unnecessary location, and will inadvertently continuefast-forward operation into important playback locations.

SUMMARY OF THE INVENTION

Accordingly, a first object of the invention is to provide an imageplayback device and method which make it possible to observe playbackimages while automatically skipping over unnecessary playback locationsby discriminating time periods with specified conditions, and performingplayback based on the results of this discrimination.

A second object of the invention is to provide an image playback deviceand method which allow direct playback of the contents of moving-pictureimage information (i.e., the flow of stories or conversations, etc.).

A third object of the invention is to provide an image playback deviceand method which make it possible to extract and playback theconversation of specified speakers, etc.

A fourth object of the invention is to provide an image playback deviceand method which make it possible to omit locations of faulty imagingcaused by backlighting, etc.

A fifth object of the invention is to provide an image playback deviceand method which make it possible to discriminate between panning scenesand scenes other than panning scenes, and to play back scenes of one orthe other type.

A sixth object of the invention is to provide an image playback deviceand method which make it possible to perform playback with locations inwhich the principal object of imaging is absent (e.g., locations inwhich only a wall is imaged, etc.) being deliberately omitted.

A seventh object of the invention is to provide an image playback deviceand method which divide moving-picture image information into imagesfrom which persons are absent and images in which persons are present,and play back images of one or the other type.

An eighth object of the invention is to provide an electronic camera andoperating method which allow (for example) observation with automaticskipping of specified playback locations by discriminating imagingparameters as conditions during imaging, and performing playback basedon the results of this discrimination.

A ninth object of the invention is to provide an electronic camera andoperating method which make it possible to perform playback withplayback locations showing an out-of-focus state omitted.

A tenth object of the invention is to provide an electronic camera andoperating method which make it possible to perform playback withlocations imaged at a lens position at the point-blank end omitted.

An eleventh object of the invention is to provide an electronic cameraand operating method which make it possible to divide moving-pictureimage information into scenery images, etc., and images other thanscenery images, etc., and to play back images of one or the other type.

A twelfth object of the invention is to provide an electronic camera andoperating method which allow (for example) observation with automaticskipping of specified playback locations by discriminating thesurrounding environment as conditions during imaging, and performingplayback based on the results of this discrimination.

A thirteenth object of the invention is to provide an electronic cameraand operating method which make it possible to perform playback in whichimages of objects that have a specified surface temperature areextracted.

Briefly stated, in one of its broader aspects, the present inventioncomprises a medium playback means which reads out recorded informationfrom a recording medium, a time period discriminating means whichreceives the recorded information read out by the image playback meansand discriminates periods of time during which the recorded informationagrees with at least one pre-set condition, and a playback display meanswhich plays back and displays moving-picture image information containedin the recorded information in accordance with results of thediscrimination performed by the time period discriminating means.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described in conjunction with theaccompanying drawings, which illustrate preferred (best mode)embodiments and illustrative implementations, and the figures of whichare briefly described hereinafter.

FIG. 1 is a block diagram illustrating a first (general) embodiment ofthe invention.

FIG. 2 is a block diagram illustrating a second embodiment.

FIG. 3 is a block diagram illustrating a third embodiment.

FIG. 4 is a block diagram illustrating a fourth embodiment.

FIG. 5 is a block diagram illustrating a fifth embodiment.

FIG. 6 is a block diagram illustrating a sixth embodiment.

FIG. 7 is a block diagram illustrating a seventh embodiment.

FIG. 8 is a block diagram illustrating an eighth embodiment.

FIG. 9 is a block diagram illustrating a ninth embodiment.

FIG. 10 is a block diagram illustrating a tenth embodiment.

FIG. 11 is a block diagram illustrating a first illustrativeimplementation of the invention.

FIG. 12 is a perspective view illustrating the external appearance ofthe first illustrative implementation of the invention.

FIG. 13 is a flow chart illustrating the operation of the firstillustrative implementation of the invention.

FIG. 14 is a block diagram illustrating a second illustrativeimplementation of the invention.

FIG. 15 is a flow chart illustrating the operation of the secondillustrative implementation of the invention.

FIG. 16 is a block diagram of a third illustrative implementation of theinvention.

FIG. 17 is a flow chart illustrating the operation of the thirdillustrative implementation of the invention.

FIG. 18 is a block diagram of a fourth illustrative implementation ofthe invention.

FIG. 19 is a flow chart illustrating the operation of the fourthillustrative implementation of the invention.

FIG. 20 is a block diagram of a fifth illustrative implementation of theinvention.

FIG. 21 is a flow chart illustrating the operation of the fifthillustrative implementation of the invention.

FIG. 22 is a block diagram of a sixth illustrative implementation of theinvention.

FIG. 23 is a flow chart illustrating the operation of the sixthillustrative implementation of the invention.

FIG. 24 is a block diagram of a seventh illustrative implementation ofthe invention.

FIGS. 25 and 26 are flow charts illustrating the operation of theseventh illustrative implementation of the invention.

FIG. 27 is a block diagram of an eighth illustrative implementation ofthe invention.

FIG. 28 is a flow chart illustrating the operation of the eighthillustrative implementation of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS AND ILLUSTRATIVE IMPLEMENTATIONS

FIG. 1 is a block diagram which illustrates a first (general) embodimentof the invention.

The invention shown in FIG. 1 is characterized by the fact that an imageplayback device is equipped with a medium playback means 1 which readsout recorded information that has been recorded on a recording medium R,a time period discriminating means 2 which receives the recordedinformation read out by the image playback means 1 and discriminatesperiods of time during which the recorded information agrees with atleast one pre-set condition, and a playback display means 3 which playsback and displays moving-picture image information contained in therecorded information in accordance with the results of thediscrimination performed by the time period discriminating means 2.

FIG. 2 is a block diagram which illustrates a second embodimentinvention.

The second embodiment is characterized by the fact that in the imageplayback device of the first embodiment, a time period discriminatingmeans 2 is equipped with a sound quantity detection means 4 whichreceives audio information from the recorded information read out by themedium playback means 1, and detects the quantity of sound of this audioinformation, and a silence discriminating means 5 which discriminatessilent periods in which the quantity of sound detected by the soundquantity detection means 4 drops below a predetermined sound quantity,and by the fact that the playback display means 3 plays back anddisplays moving-picture image information contained in the recordedinformation only during time periods other than the silent periodsdiscriminated by the silence discriminating means 5.

FIG. 3 is a block diagram which illustrates the third embodiment of theinvention.

The third embodiment is characterized by the fact that in the imageplayback device of the first embodiment, the time period discriminatingmeans 2 is equipped with a speaker characteristic feature extractingmeans 6 which receives audio information from the recorded informationread out by the medium playback means 1, and detects at least onecharacteristic feature parameter specifying long-term spectrum averagesor mean pitch frequencies for the audio information; and a speakerdiscriminating means 7 which discriminates time periods during which thecharacteristic feature parameters detected by the speaker characteristicfeature extracting means 6 show agreement with pre-registeredcharacteristic feature parameters within permissible ranges, and by thefact that the playback display means 3 plays back and displaysmoving-picture image information contained in the recorded informationonly during time periods discriminated by the speaker discriminatingmeans 7.

FIG. 4 is a block diagram of the fourth embodiment of the invention.

The fourth embodiment is characterized by the fact that in the imageplayback device of the first embodiment, the time period discriminatingmeans 2 is equipped with a brightness difference detection means 8 whichinputs moving-picture image information from the recorded informationread out by the medium playback means 1, and detects differences in thebrightness level between central and peripheral portions of an imagescreen, and a backlighting discriminating means 9 which discriminatesperiods of backlighting (in which imaging is performed under backlitconditions) based on the brightness level differences detected by thebrightness difference detection means 8, and by the fact that theplayback display means 3 plays back and displays moving-picture imageinformation contained in the recorded information only during timeperiods other than the periods of backlighting discriminated by thebacklighting discriminating means 9.

FIG. 5 is a block diagram of a fifth embodiment of the invention.

The fifth embodiment is characterized by the fact that in the imageplayback device of the first embodiment, the time period discriminatingmeans 2 is equipped with a movement detection means 10 which receivesmoving-picture image information from the recorded information read outby the medium playback means 1, and detects movement vectors betweenmoving-picture frames, and a panning discriminating means 11 whichdiscriminates panning periods (in which the screen as a whole moveshorizontally) from the movement vectors detected by the movementdetection means 10, and by the fact that the playback display means 3acquires the panning periods discriminated by the panning discriminatingmeans 11, and plays back and displays moving-picture image informationcontained in the recorded information only during the panning periods orduring time periods other than the panning periods.

FIG. 6 is a block diagram of the sixth embodiment of the invention.

The sixth embodiment is characterized by the fact that in the imageplayback device of the first embodiment, the time period discriminatingmeans 2 is equipped with a contrast detection means 12 which receivesmoving-picture image information from the recorded information read outby the medium playback means 1, and detects the contrast of thismoving-picture image information, and a low-contrast discriminatingmeans 13 which discriminates low-contrast periods in which the contrastdetected by the contrast detection means 12 drops below a predeterminedthreshold value, and by the fact that the playback display means 3 playsback and displays moving-picture image information contained in therecorded information only during time periods other than thelow-contrast periods discriminated by the low-contrast discriminatingmeans 13.

FIG. 7 is a block diagram of the seventh embodiment of the invention.

The seventh embodiment is characterized by the fact that in the imageplayback device of the first embodiment, the time period discriminatingmeans 2 is equipped with a flesh tone detection means 14 which receivesmoving-picture image information from the recorded information read outby the medium playback means 1, and detects flesh tone regions withinthe screen, and an absence-of-persons discriminating means 15 whichdiscriminates periods of absence of persons in which the flesh toneregions detected by the flesh tone detection means 14 drop below aprescribed area, and by the fact that the playback display means 3acquires the periods of absence of persons discriminated by theabsence-of-persons discriminating means 15, and plays back and displaysmoving-picture image information contained in the recorded informationonly during these periods of absence of persons or during time periodsother than these periods of absence of persons.

FIG. 8 is a block diagram which illustrates the eighth embodiment of theinvention.

The eight embodiment is characterized by the fact that an electroniccamera is equipped with an imaging means 16 which producesmoving-picture image information by imaging an object via an imagingoptical system L, an imaging parameter detection means 17 which detectsat least one imaging parameter of the imaging optical system L, a mediumrecording means 18 which inputs moving-picture image informationproduced by the imaging means 16 and imaging parameters detected by theimaging parameter detection means 17, and records such moving-pictureimage information and imaging parameter on a recording medium R asrecorded information, a medium playback means 1 which reads out therecorded information from the recording medium R, a time perioddiscriminating means 19 which receives at least one imaging parameterfrom the recorded information read out by the medium playback means 1,and discriminates time periods during which such imaging parametersagree with certain pre-set conditions, and a playback display means 3which plays back and displays moving-picture image information containedin the recorded information in accordance with the results of thediscrimination performed by the time period discriminating means 19.

In one of its implementations, the eight embodiment is characterized bythe fact that in the electronic camera, the imaging parameter detectionmeans 17 detects focal point adjustment conditions of the imagingoptical system L as imaging parameters, the time period discriminatingmeans 19 receives the focal point adjustment conditions from therecorded information read out by the medium playback means 1, anddiscriminates out-of-focus periods in which the focal point adjustmentconditions show an out-of-focus state, and the playback display means 3plays back and displays moving-picture image information contained inthe recorded information only during time periods other than theout-of-focus periods detected by the time period discriminating means19.

In another of its implementations, the eighth embodiment ischaracterized by the fact that in the electronic camera, the imagingparameter detection means 17 detects the lens position inside a mirrortube of the imaging optical system L as an imaging parameter, the timeperiod discriminating means 19 receives the lens position from therecorded data read out by the medium playback means 1, and discriminatespoint-blank periods in which the lens position is at the point-blank(close distance) end, and the playback display means 3 plays back anddisplays moving-picture image information contained in the recordedinformation only during time periods other than the point-blank periodsdiscriminated by the time period discriminating means 19.

In another of its implementations, the eighth embodiment ischaracterized by the fact that in the electronic camera, the imagingparameter detection means 17 detects the lens position inside a mirrortube of the imaging optical system L as an imaging parameter, the timeperiod discriminating means 19 receives the lens position from therecorded data read out by the medium playback means 1, and discriminatesperiods of infinite distance in which the lens position is at theinfinite distance end, and the playback display means 3 plays back anddisplays moving-picture image information contained in the recordedinformation only during the periods of infinite distance discriminatedby the time period discriminating means 19 or during time periods otherthan the periods of infinite distance.

FIG. 9 is a block diagram of the ninth embodiment of the invention.

The ninth embodiment is characterized by the fact that an electroniccamera of this invention is equipped with an imaging means 16 whichproduces moving-picture image information by imaging an object via animaging optical system L, an environmental parameter detection means 20which detects at least one environmental parameter indicative of thesurrounding environment at the time of imaging, a medium recording means18 which inputs moving-picture image information produced by the imagingmeans 16 and environmental parameters detected by the environmentalparameter detection means 20, and records such moving-picture imageinformation and environmental parameters on a recording medium R asrecorded information, a medium playback means 1 which reads out therecorded information from the recording medium R, a time perioddiscriminating means 21 which receives the environmental parameters fromthe recorded information read out by the medium playback means 1, anddiscriminates time periods during which these environmental parametersagree with certain pre-set conditions, and a playback display means 3which plays back and displays moving-picture image information containedin the recorded information in accordance with the results of thediscrimination performed by the time period discriminating means 21.

FIG. 10 is a block diagram which illustrates the tenth embodiment of theinvention.

The tenth embodiment is characterized by the fact that in the electroniccamera of the ninth embodiment, the environmental parameter detectionmeans 20 is equipped with an infrared radiation detection means 22 whichdetects infrared radiation from an imaged object field, and atemperature detection means 23 which detects the temperature of theobject in accordance with the infrared radiation detected by theinfrared radiation detection means 22, and uses this temperature of theobject as an environmental parameter, by the fact that the time perioddiscriminating means 21 receives the temperature of the object from therecorded information read out by the medium playback means 1, anddiscriminates periods in which the temperature of the object is within apredetermined temperature range, and the playback display means 3 playsback and displays moving-picture image information contained in therecorded information only during the periods discriminated by the timeperiod discriminating means 21 or during time periods other than theperiods discriminated by the time period discriminating means 21.

In the image playback device of FIG. 1, recorded information is read outfrom the recording medium R via the medium playback means 1.

The time period discriminating means 2 discriminates this recordedinformation using pre-set conditions, and determines time periods inwhich the recorded information shows agreement with these conditionswithin the playback period of the recorded information.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information in accordancewith the results of such a discrimination.

Furthermore, it is sufficient if the playback display means 3 used hereis a means which produces an image output, etc., that is provided to animage display device; it is not necessary to include such an imagedisplay device itself.

In the image playback device of FIG. 2, the time period discriminatingmeans 2 is constructed from a sound quantity detection means 4 and asilence discriminating means 5.

This sound quantity detection means 4 inputs audio information from therecorded information, and detects the sound quantity of this audioinformation.

The silence discriminating means 5 discriminates silent periods in whichthe above-mentioned sound quantity drops below a predetermined soundquantity.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information, with theabove-mentioned silent periods omitted.

As a result of such an action, moving-picture image information can beplayed back and displayed with an emphasis on conversational portions ornarration portions contained in the recorded information. Accordingly,the operator can obtain a rough grasp of the contents of the recordedinformation (story or flow of conversation) without playing back therecorded information over the entire time period of this recordedinformation.

In the image playback device of FIG. 3, the time period discriminatingmeans 2 is constructed from a speaker characteristic feature extractingmeans 6 and a speaker discriminating means 7.

The speaker characteristic feature extracting means 6 inputs audioinformation from the recorded information, and detects characteristicfeature parameters (long-term spectrum averages or mean pitchfrequencies) of this audio information.

The speaker discriminating means 7 discriminates periods in which thesecharacteristic feature parameters agree with registered characteristicfeature parameters within a permissible range.

The playback display device 3 plays back and displays moving-picturecontained in the recorded information only during these periods ofagreement.

As a result of such an action, moving-picture image information can beplayed back and displayed with an emphasis on conversations of specifiedspeakers, etc., within the recorded information. Accordingly, theoperator can observe moving-picture image information with an emphasison specified speakers.

In the image playback device of FIG. 4, the time period discriminatingmeans 2 is constructed from a brightness difference detection means 8and a backlighting discriminating means 9.

This brightness difference detection means 8 inputs moving-picture imageinformation from the recorded information, and detects differences inthe brightness level between central and peripheral portions of theimage screen.

The backlighting discriminating means 9 discriminates backlightingperiods (in which imaging is performed in a backlit state) based on thebrightness level differences.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information, with thebacklighting periods omitted.

As a result of such an action, moving-picture image information isplayed back and displayed with portions consisting of backlit imagingomitted. Accordingly, the operator can observe moving-picture imageinformation with periods of faulty imaging, etc., caused by backlightingomitted.

In the image playback device of FIG. 5, the time period discriminatingmeans 2 is constructed from a movement detection means 10 and a panningdiscriminating means 11.

The movement detection means 10 inputs moving-picture image informationfrom the recorded information, and detects movement vectors betweenmoving-picture frames.

The panning discriminating means 11 discriminates panning periods (inwhich the image screen as a whole moves horizontally) from the movementvectors.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information only during suchpanning periods or during time periods other than these panning periods.

Here, in cases where playback and display are performed only duringpanning periods, the operator can view moving-picture image informationwith an emphasis on scenes from car windows, etc.

On the other hand, in cases where playback and display are performedonly during time periods other than panning periods, the operator canview moving-picture image information with unnecessary panning portions(generated when scenes separated by a distance are connected), etc.,excluded.

In the image playback device of FIG. 6, the time period discriminatingmeans 2 is constructed from a contrast detection means 12 and alow-contrast discriminating means 13.

The above-mentioned contrast detection means 12 inputs moving-pictureimage information from the recorded information, and detects thecontrast of this moving-picture image information.

The low-contrast discriminating means 13 discriminates low-contrastperiods in which the contrast drops below a predetermined thresholdvalue.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information, with thelow-contrast periods omitted.

As a result of this action, moving-picture image information is playedback and displayed with low-contrast portions omitted. Accordingly, theoperator can view moving-picture image information with low-contrastportions in which the main object of imaging is not present (as inimages of blank walls, for example) omitted.

In the image playback device of FIG. 7, the time period discriminatingmeans 2 is constructed from a flesh tone detection means 14 and anabsence-of-persons discriminating means 15.

The flesh tone detection means 14 inputs moving-picture imageinformation from the recorded information, and detects regionscorresponding to flesh tones (hereafter referred to as “flesh toneregions”) within the image screen.

The absence-of-persons discriminating means 15 discriminates periods ofabsence of persons in which the flesh tone regions drop below aprescribed area.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information only during suchperiods of absence of persons or during time periods other than theseperiods of absence of persons.

Here, in cases where playback and display are performed only duringperiods of absence of persons, the operator can view moving-pictureimage information with an emphasis on portions of the image informationin which no persons are present, such as background images, etc.

On the other hand, in cases where playback and display are performedonly during time periods other than the above-mentioned periods ofabsence of persons, the operator can view moving-picture imageinformation with an emphasis on portions of the image information inwhich persons are imaged.

In the electronic camera of FIG. 8, the imaging parameter detectionmeans 17 detects imaging parameters which indicate the conditions of theimaging optical system L, etc., during imaging.

The medium recording means 18 records such imaging parameters on therecording medium R together with moving-picture image information.

At the time of playback, the time period discriminating means 19 inputsat least one imaging parameter from the recorded information that isread out. The time period discriminating means 19 discriminates suchimaging parameters using pre-set conditions, and determines time periodsin which the parameters agree with these conditions within the playbackperiod of the recorded information.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information in accordancewith the results of such a discrimination.

Furthermore, it is sufficient if the playback display means 3 used hereis a means which produces an image output, etc., that is provided to animage display device; it is not particularly necessary to include suchan image display device itself.

In one the implementations of the eighth embodiment, focal pointadjustment conditions of the imaging optical system L are recordedtogether with moving-picture image information at the time of imaging.

The time period discriminating means 19 inputs the focal pointadjustment conditions from the recorded information, and discriminatesout-of-focus periods in which the focal point adjustment conditions showan out-of-focus state.

The playback display means 3 plays back and displays moving-pictureimage information only during time periods other than such out-of-focusperiods.

As a result of such an action, moving-picture image information isplayed back and displayed with out-of-focus portions omitted.Accordingly, the operator can view moving-picture image information withperiods of faulty imaging, etc., caused by improper focusing omitted.

Furthermore, in regard to the above-mentioned focal point adjustmentconditions, it is possible to use either a numerical value whichindicates the amount of defocusing, etc., or flag information whichindicates whether or not an out-of-focus state exists, etc.

In another implementation of the eighth embodiment, the lens position ofthe imaging optical system L is recorded together with moving-pictureimage information at the time of imaging.

At the time of playback, the time period discriminating means 19 inputsthe lens position from the recorded information, and discriminatespoint-blank periods in which this lens position shows a position at thepoint-blank end.

The playback display means 3 plays back and displays moving-pictureimage information only during time periods other than these point-blankperiods.

As a result of such an action, moving-picture image information isplayed back and displayed with portions imaged under conditions in whichthe lens position of the imaging optical system L is at the point-blankend omitted. Accordingly, moving-picture image information can be viewedwith images of obstacles, etc., passing immediately in front of theelectronic camera omitted.

In another implementation of the eighth embodiment, the lens position ofthe imaging optical system L is recorded together with moving-pictureimage information at the time of imaging.

At the time of playback, the time period discriminating means 19 inputsthe lens position from the recorded information, and discriminatesperiods of infinite distance in which this lens position shows aposition at the infinite distance end.

The playback display means 3 plays back and displays moving-pictureimage information only during such periods of infinite distance orduring time periods other than such periods of infinite distance.

Here, in cases where playback and display are performed only during theperiods of infinite distance, the operator can view moving-picture imageinformation with an emphasis on objects that are imaged at the infinitedistance end, such as scenery, etc.

On the other hand, in cases where playback and display are performedonly during time periods other than the periods of infinite distance,the operator can view moving-picture image information with objects ofimaging that are imaged at the infinite distance end, such as scenery,etc., omitted.

In the electronic camera of FIG. 9, the environmental parameterdetection means 20 detects environmental parameters indicative of thesurrounding environment at the time of imaging.

The medium recording means 18 records such environmental parameters onthe recording medium R together with moving-picture image information.

At the time of playback, the time period discriminating means 21 inputsthe environmental parameters from the recorded information that is readout. The time period discriminating means discriminates theseenvironmental parameters using pre-set conditions, and determinesperiods in which these parameters show agreement with theabove-mentioned conditions during the playback period of the recordedinformation.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information in accordancewith the results of such a discrimination.

Furthermore, it is sufficient if the playback display means 3 used hereis a means which produces an image output, etc., that is provided to animage display device; it is not particularly necessary to include suchan image display device itself.

In the electronic camera of FIG. 10, the environmental parameterdetection means 20 is constructed from an infrared radiation detectionmeans 22 and a temperature detection means 23.

The infrared radiation detection means 22 detects infrared radiationfrom the image field at the time of imaging.

The temperature detection means 23 detects a numerical value which isconvertible into the surface temperature of the object (hereafter, thisnumerical value will be referred to as the “temperature of the object”)based on the above-mentioned infrared radiation.

The medium recording means 18 records this temperature of the object onthe recording medium R together with moving-picture image information.

At the time of playback, the time period discriminating means 21 inputsthe temperature of the object from the recorded information. The timeperiod discriminating means 21 discriminates periods during which thetemperature of the object is within a predetermined temperature range.

The playback display means 3 plays back and displays moving-pictureimage information contained in the recorded information only during theperiods discriminated by the time period discriminating means 21 orduring time periods other than the periods discriminated by the timeperiod discriminating means 21.

As a result of such an action, moving-picture image information can beviewed with an emphasis on objects that exhibit a temperature within aspecified range, or on objects other than such objects.

Illustrative implementations of the invention will now be described.

FIG. 11 is a block diagram which illustrates a first illustrativeimplementation of the invention (corresponding to FIG. 2).

FIG. 12 is a perspective view which illustrates the external appearanceof the present illustrative implementation of the invention.

In these figures, a disk drive part 33 in which an optical-magneticrecording medium 32 is mounted in a freely detachable manner isinstalled in the image playback device 31. This disk drive part 33 isconnected to a micro-processor 35 via a system bus 34.

Furthermore, a memory 36, an image expansion part 37, a display memory38, an audio D/A conversion part 39 and a sound quantity detection part40 a are individually connected to the system bus 34.

A liquid crystal display part 42 is connected to the display memory 38via a liquid crystal driving circuit 41.

A speaker 44 is connected to the audio D/A conversion part 39 via anaudio amplifier 43.

The output of the sound quantity detection part 40 a is input into themicro-processor 35 via a silence discriminating part 45 a.

Furthermore, a playback button 46 is installed in the housing of theimage playback device 31, and the output of this playback button 46 isinput into the micro-processor 35.

Here, in regard to the correspondence between the invention shown inFIG. 2 and the first illustrative implementation of the invention shownin FIG. 11, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to the soundquantity detection part 40 a and silence discriminating part 45 a, andthe playback display means 3 corresponds to the image expansion part 37,display memory 38, liquid crystal driving circuit 41 and themicro-processor 35.

The operation of the first illustrative implementation of the inventionwill be described with reference to FIGS. 11 through 13.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 13 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files.

The disk drive part 33 reads out image files from the optical-magneticrecording medium 32, and successively stores these image files in thememory 36 (FIG. 13 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 13S3).

The sound quantity detection part 40 a inputs audio information(recorded in synchronization with the images having the above-mentionedplayback frame numbers) from the image files at fixed intervals, anddetects the sound quantity level of this audio information (FIG. 13 S4).

The silence discriminating part 45 a ascertains whether or not theabove-mentioned sound quantity level has dropped below a predeterminedthreshold value (FIG. 13 S5).

Here, if the sound quantity level exceeds the above-mentionedpredetermined threshold value (NO side of FIG. 13 S5), themicro-processor 35 instructs the image expansion part 37 to performimage expansion. The image expansion part 37 inputs moving-picture imageinformation indicated by the above-mentioned playback frame numbers fromthe image files, performs image expansion, and stores the information inthe display memory 38 (FIG. 13 S6).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 13 S7). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

On the other hand, in cases where the sound quantity level is below theabove-mentioned predetermined threshold value (YES side of FIG. 13 S5),the image expansion part 37 performs only intra-frame image expansion,and the resulting information is temporarily recorded in a workingmemory within the image expansion part 37 (FIG. 13 S8). Theseintra-frame images are images obtained by intra-frame compression atfixed frame intervals within the moving-picture image information, andare images necessary for the image expansion of other images (imagessubjected to inter-frame compression).

Following the completion of such processing (FIG. 13 S7 or S8), themicro-processor 35 advances the playback frame number by one step (FIG.13 S9).

Here, in cases where the playback of the moving-picture imageinformation has not been completed (NO side of FIG. 13 S10), theoperation returns to the processing of FIG. 13 S4, and the operationsdescribed above are repeated.

On the other hand, when the playback of moving-picture image informationis completed to the last frame number (YES side of FIG. 13 S10), theimage file playback operation is completed. Furthermore, at this time,the temporary recording of intra-frame images is also erased.

As a result of the above operation, image files are not played back anddisplayed in the case of silent periods in which the sound quantitylevel is below the above-mentioned threshold value; instead, only theplayback frame numbers increase at a high rate. Accordingly,moving-picture image information in time periods other than theabove-mentioned silent periods can be selectively played back anddisplayed.

Furthermore, as a result of such playback and display, image files canbe played back and displayed with an emphasis on conversational portionsor narration portions, etc., contained in the image files. Accordingly,the operator can obtain a quick grasp of the flow of stories orconversation, etc., without having to view all of the image files.

FIG. 14 is a block diagram of a second illustrative implementation ofthe invention (corresponding to FIG. 3).

The structural special features of the second illustrativeimplementation of the invention are as follows:

(1) A speaker characteristic feature extracting part 40 b and a speakerdiscriminating part 45 b are respectively installed instead of the soundquantity detection part 40 a and silence discriminating part 45 a shownin FIG. 11.

(2) A speaker registration button 47 is installed in the housing of theimage playback device 31, and the output of this speaker registrationbutton 47 is input into the speaker discriminating part 45 b.

Constituent elements which are the same as constituent elements shown inFIG. 11 are labeled with the same reference numbers in FIG. 14, and adescription of the construction of such elements is omitted here.

Here, in regard to the correspondence between the invention shown inFIG. 3 and the second illustrative implementation of the invention shownin FIG. 14, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to thespeaker characteristic feature extracting part 40 b and speakerdiscriminating part 45 b, and the playback display means 3 correspondsto the image expansion part 37, display memory 38, liquid crystaldriving circuit 41 and the micro-processor 35.

The operation of the second illustrative implementation of the inventionwill be described with reference to FIGS. 14 and 15.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor 35 enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 15 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files.

The disk drive part 33 reads out image files from the optical-magneticrecording medium 32, and successively stores these image files in thememory 36 (FIG. 15 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 15S3).

The speaker characteristic feature extracting part 40 b inputs audioinformation (recorded in synchronization with the images having theabove-mentioned playback frame numbers) from the image files in thememory 36 at fixed intervals, and detects universally known long-termspectrum averages (FIG. 15 S4).

When the speaker registration button 47 is pressed in this state (FIG.15 S5), the speaker discriminating part 45 b stores the detectedlong-term spectrum average data as registered data (FIG. 15 S6).

Here, the speaker discriminating part 45 b ascertains whether or notdetected long-term spectrum average data agrees with the above-mentionedregistered data within a permissible range (FIG. 15 S7). Furthermore, incases where the registered data has not been registered, the speakerdiscriminating part 45 b makes a uniform judgement of “agreement”.

If characteristic feature parameters show agreement within a permissiblerange (YES side of FIG. 15 S7), the micro-processor 35 instructs theimage expansion part 37 to perform image expansion. The image expansionpart 37 inputs moving-picture image information (indicated by playbackframe numbers) from image files, performs image expansion, and transfersthe information to the display memory 38 (FIG. 15 S8).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 15 S9). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

In cases where the long-term spectrum average data does not agree withthe registered data within the above-mentioned permissible range (NOside of FIG. 15 S7), the image expansion part 37 expands only theintra-frame images required for the image expansion of the preceding andfollowing frames. This intra-frame image [information] is temporarilyrecorded in the image expansion part 37 (FIG. 15 S10). Here, since theintra-frame images are not stored in the display memory 38, these imagesare not played back and displayed.

After such processing (FIG. 15 S9 or S10) has been completed, themicro-processor 35 advances the playback frame number by one step (FIG.15 S11).

Here, in cases where the playback of the moving-picture imageinformation has not been completed (NO side of FIG. 15 S12), theoperation returns to the processing of FIG. 15 S4, and the operationsdescribed above are repeated.

On the other hand, when the playback of moving-picture image informationis completed to the last frame number (YES side of FIG. 15 S12), theimage file playback operation is completed. Furthermore, at this time,the temporary recording of intra-frame images is also erased.

As a result of the above operation, image files are not played back anddisplayed during time periods other than periods of conversation byspecified speakers; instead, only the frame numbers change at a highrate. Consequently, playback and display are performed with an emphasison moving-picture image information corresponding to periods ofconversation by specified speakers.

Accordingly, the operator can view moving-picture image informationselectively, with an emphasis on conversation by specified speakers.

FIG. 16 is a block diagram of a third illustrative implementation of theinvention (corresponding to FIG. 4).

In structural terms, this third illustrative implementation of theinvention is characterized by the fact that a brightness differencedetection part 40 c and a backlighting discriminating part 45 c arerespectively installed instead of the sound quantity detection part 40 aand silence discriminating part 45 a shown in FIG. 11.

Furthermore, constituent elements which are the same as constituentelements shown in FIG. 11 are labeled with the same reference numbers inFIG. 16, and a description of the construction of such elements isomitted here.

Here, in regard to the correspondence between the invention shown inFIG. 4 and the third illustrative implementation of the invention shownin FIG. 16, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to thebrightness difference detection part 40 c and backlightingdiscriminating part 45 c, and the playback display means 3 correspondsto the image expansion part 37, display memory 38, liquid crystaldriving circuit 41 and of the micro-processor 35.

The operation of the third illustrative implementation of the inventionwill be described with reference to FIGS. 16 and 17.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor 35 enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 17 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files. The disk drive part 33 reads out image files from theoptical-magnetic recording medium 32, and successively stores theseimage files in the memory 36 (FIG. 17 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 17S3).

Here, the micro-processor 35 instructs the image expansion part 37 toperform image expansion of intra-frame images. The image expansion part37 inputs intra-frame images indicated by the playback frame numbersfrom image files in the memory 36, and performs image expansion on theseintra-frame images (FIG. 17 S4).

The brightness difference detection part 40 c inputs the intra-frameimages following image expansion, and detects differences in thebrightness level between central and peripheral portions of the imagescreen (FIG. 17 S5).

The backlighting discriminating part 45 c ascertains whether or not suchbrightness level differences exceed a predetermined threshold value(FIG. 17 S6).

Here, in cases where the brightness level differences are less than theabove-mentioned threshold value (NO side of FIG. 17 S6), themicro-processor 35 instructs the image expansion part 37 to performimage expansion up to the point immediately preceding the nextintra-frame image. The image expansion part 37 successively performsimage expansion up to the next intra-frame image, and stores theresulting image information in the display memory 38 (FIG. 17 S7).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 17 S8). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

When image expansion up to the point immediately preceding the nextintra-frame image is completed in the image expansion part 37, themicro-processor 35 advances the playback frame number to the framenumber of the next intra-frame image (FIG. 17 S9).

In cases where the above-mentioned brightness level differences exceedthe threshold value (YES side of FIG. 17 S6), the playback and displayprocessing (FIG. 17 S7 and S8) is not performed. As a result, in FIG. 17S9, only the playback frame number is advanced to the frame number ofthe next intra-frame image.

In cases where the playback of moving-picture image information is notcompleted following the above series of operations (NO side of FIG. 17S10), the operation returns to the processing of FIG. 17 S4, and theabove operations are repeated.

On the other hand, when the playback of moving-picture image informationis completed to the last frame number (YES side of FIG. 17 S10), theimage file playback operation is completed. Furthermore, at this time,the temporary recording of intra-frame images is also erased.

As a result of the above operation, image files are played back anddisplayed with backlighting periods (in which the brightness leveldifference exceeds the above-mentioned threshold value) omitted.Accordingly, the operator can view moving-picture image information withfaulty imaging portions caused by backlighting omitted.

FIG. 18 is a block diagram of a fourth illustrative implementation ofthe invention (corresponding to FIG. 5).

In structural terms, this fourth illustrative implementation of theinvention is characterized by the fact that a movement detection part 40d and a panning discriminating part 45 d are respectively installedinstead of the sound quantity detection part 40 a and silencediscriminating part 45 a shown in FIG. 11.

Furthermore, constituent elements which are the same as constituentelements shown in FIG. 11 are labeled with the same reference numbers inFIG. 18, and a description of the construction of such elements isomitted here.

Here, in regard to the correspondence between the invention shown inFIG. 5 and the fourth illustrative implementation of the invention shownin FIG. 18, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to themovement detection part 40 d and panning discriminating part 45 d, andthe playback display means 3 corresponds to the image expansion part 37,display memory 38, liquid crystal driving circuit 41 and of themicro-processor 35.

The operation of the fourth illustrative implementation of the inventionwill be described with reference to FIGS. 18 and 19.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor 35 enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 19 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files. The disk drive part 33 reads out image files from theoptical-magnetic recording medium 32, and successively stores theseimage files in the memory 36 (FIG. 19 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 19S3).

The movement detection part 40 d acquires universally known movementvectors from the moving-picture image information indicated by theplayback frame numbers (FIG. 19 S4). These movement vectors consist ofvector information which digitizes the movement in images between frameswhen inter-frame compression of the moving-picture image information isperformed. Since these movement vectors are also used for imageexpansion during playback, the vectors are assigned to moving-pictureimage information following compression, and are recorded.

The panning discriminating part 45 d ascertains from the above-mentionedmovement vectors whether or not the screen as a whole is in the processof parallel movement (FIG. 19 S5).

Here, in cases where the screen as a whole is not undergoing parallelmovement (NO side of FIG. 19 S5), the micro-processor 35 instructs theimage expansion part 37 to perform image expansion. The image expansionpart 37 inputs the moving-picture image information indicated by theplayback frame numbers from the image files, performs image expansion,and stores the resulting image information in the display memory 38(FIG. 19 S6).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 19 S7). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

In cases where the screen as a whole is in the process of horizontalmovement (YES side of FIG. 19 S5), the image expansion part 37 expandsonly the intra-frame images, and the resulting image information istemporarily stored in a working memory contained in the image expansionpart 37 (FIG. 19 S8). These intra-frame images are used for imageexpansion of the preceding and following frames, and are not played backand displayed.

After such processing (FIG. 19 S7 or S8) has been completed, themicro-processor 35 advances the playback frame number by one step (FIG.19 S19).

Here, in cases where the playback of the moving-picture imageinformation has not been completed (NO side of FIG. 19 S10), theoperation returns to the processing of FIG. 19 S4, and the operationsdescribed above are repeated.

On the other hand, when the playback of moving-picture image informationis completed with frame number reaching the last number (YES side ofFIG. 19 S10), the image file playback operation is completed.Furthermore, at this time, the temporary recording of intra-frame imagesis also erased.

As a result of the above operation, image files are played back anddisplayed with panning periods omitted. Accordingly, the operator canview moving-picture image information with panning portions (insertedincidentally for the purpose of connecting scenes) omitted.

FIG. 20 is a functional block diagram of a fifth illustrativeimplementation of the invention (corresponding to FIG. 6).

In structural terms, this fifth illustrative implementation of theinvention is characterized by the fact that a contrast detection part 40e and a low-contrast discriminating part 45 e are respectively installedinstead of the sound quantity detection part 40 a and silencediscriminating part 45 a shown in FIG. 11.

Furthermore, constituent elements which are the same as constituentelements shown in FIG. 11 are labeled with the same reference numbers inFIG. 20, and a description of the construction of such elements isomitted here.

Here, in regard to the correspondence between the invention shown inFIG. 6 and the fifth illustrative implementation of the invention shownin FIG. 20, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to thecontrast detection part 40 e and low-contrast discriminating part 45 e,and the playback display means 3 corresponds to the image expansion part37, display memory 38, liquid crystal driving circuit 41 and themicro-processor 35.

The operation of the fifth illustrative implementation of the inventionwill be described with reference to FIGS. 20 and 21.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor 35 enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 21 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files.

The disk drive part 33 reads out image files from the optical-magneticrecording medium 32, and successively stores these image files in thememory 36 (FIG. 21 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 21S3).

Here, the micro-processor 35 instructs the image expansion part 37 toperform image expansion on intra-frame images. The image expansion part37 inputs the intra-frame images indicated by the playback frame numbersfrom the image files, and performs image expansion on these intra-frameimages (FIG. 21 S4).

The contrast detection part 40 e inputs intra-frame images followingimage expansion, extracts the high-region components of the spacefrequency, and detects the amount of contrast (FIG. 21 S5).

The low-contrast discriminating part 45 e ascertains whether or not thisamount of contrast is less than a predetermined threshold value (FIG. 21S6).

Here, in cases where the amount of contrast exceeds the above-mentionedthreshold value (NO side of FIG. 21 S6), the micro-processor 35instructs the image expansion part 37 to perform image expansion up tothe point immediately preceding the next intra-frame image. The imageexpansion part 37 successively performs image expansion up to the nextintra-frame image, and stores the resulting image information in thedisplay memory 38 (FIG. 21 S7).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 21 S8). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

When image expansion up to the point immediately preceding the nextintra-frame image is completed in the image expansion part 37, themicro-processor 35 advances the playback frame number to the framenumber of the next intra-frame image (FIG. 21 S9).

In cases where the above-mentioned amount of contrast is less than thethreshold value (YES side of FIG. 21 S6), the playback and displayprocessing (FIG. 21 S7 and S8) is not performed. As a result, in FIG. 21S9, only the playback frame number is advanced to the frame number ofthe next intra-frame image.

In cases where the playback of moving-picture image information is notcompleted after the above series of operations has been completed (NOside of FIG. 21 S10), the operation returns to the processing of FIG. 21S4, and the above operations are repeated.

On the other hand, when the playback of moving-picture image informationis completed with frame number reaching the last number (YES side ofFIG. 21 S10), the image file playback operation is completed.Furthermore, at this time, the temporary recording of intra-frame imagesis also erased.

As a result of the above operation, image files are played back anddisplayed with low-contrast periods (in which the amount of contrast isless than the above-mentioned threshold value) omitted. Accordingly, theoperator can view moving-picture image information with scenes of walls,etc. (in which the main objects are not imaged) omitted.

FIG. 22 is a functional block diagram of a sixth illustrativeimplementation of the invention (corresponding to FIG. 7).

In structural terms, this sixth illustrative implementation of theinvention is characterized by the fact that a flesh tone detection part40 f and an absence-of-persons discriminating part 45 f are respectivelyinstalled instead of the sound quantity detection part 40 a and silencediscriminating part 45 a shown in FIG. 11.

Furthermore, constituent elements which are the same as constituentelements shown in FIG. 11 are labeled with the same reference numbers inFIG. 22, and a description of the construction of such elements isomitted here.

Here, in regard to the correspondence between the invention shown inFIG. 7 and the sixth illustrative implementation of the invention shownin FIG. 22, the medium playback means 1 corresponds to the disk drivepart 33, the time period discriminating means 2 corresponds to the fleshtone detection part 40 f and absence-of-persons discriminating part 45f, and the playback display means 3 corresponds to the image expansionpart 37, display memory 38, liquid crystal driving circuit 41 and themicro-processor 35.

The operation of the sixth illustrative implementation of the inventionwill be described with reference to FIGS. 22 and 23.

First, when the main power supply of the image playback device 31 isswitched on, the micro-processor 35 enters a waiting state until theplayback button 46 is switched on.

When the playback button 46 is switched on (FIG. 23 S1) in this state,the micro-processor 35 instructs the disk drive part 33 to read outimage files.

The disk drive part 33 reads out image files from the optical-magneticrecording medium 32, and successively stores these image files in thememory 36 (FIG. 23 S2).

Meanwhile, the micro-processor 35 resets the playback frame numbers ofthe image files stored at prescribed addresses in the memory 36 (FIG. 23S3).

Here, the micro-processor 35 instructs the image expansion part 37 toperform image expansion on intra-frame images. The image expansion part37 inputs the intra-frame images indicated by the playback frame numbersfrom the image files in the memory 36, and performs image expansion onthese intra-frame images (FIG. 23 S4).

The flesh tone detection part 40 f inputs intra-frame images followingimage expansion, extracts image regions which resemble flesh tones(flesh tone regions), and counts the number of pixels in such flesh toneregions (FIG. 23 S5).

The absence-of-persons discriminating part 45 f ascertains whether ornot the number of pixels of the above-mentioned flesh tone regions isless than a predetermined threshold value (FIG. 23 S6).

Here, in cases where the number of pixels of the above-mentioned fleshtone regions exceeds the above-mentioned threshold value (NO side ofFIG. 23 S6), the micro-processor 35 instructs the image expansion part37 to perform image expansion up to the point immediately preceding thenext intra-frame image. The image expansion part 37 successivelyperforms image expansion up to the next intra-frame image, and storesthe resulting image information in the display memory 38 (FIG. 23 S7).

The liquid crystal driving circuit 41 reads out the moving-picture imageinformation in the display memory 38 at the rate of every other frameperiod, and displays this information on the liquid crystal display part42 (FIG. 23 S8). In this case, audio information which is synchronizedwith the moving-picture image information is played back together withthe moving-picture image information by means of the audio D/Aconversion part 39 and audio amplifier 43.

When image expansion up to the point immediately preceding the nextintra-frame image is completed in the image expansion part 37, themicro-processor 35 advances the playback frame number to the framenumber of the next intra-frame image (FIG. 23 S9).

In cases where the number of pixels of the flesh tone regions is lessthan the above-mentioned threshold value (YES side of FIG. 23 S6), theplayback and display processing (FIG. 23 S7 and S8) is not performed. Asa result, in FIG. 23 S9, only the playback frame number is advanced tothe frame number of the next intra-frame image.

In cases where the playback of moving-picture image information is notcompleted after the above series of operations has been completed (NOside of FIG. 23 S10), the operation returns to the processing of FIG. 23S4, and the above operations are repeated.

On the other hand, when the playback of moving-picture image informationis completed with the frame number reaching the last number (YES side ofFIG. 23 S10), the image file playback operation is completed.Furthermore, at this time, the temporary recording of intra-frame imagesis also erased.

As a result of the above operation, image files are played back anddisplayed with periods of absence of persons (in which the flesh toneregions have less than a prescribed area) omitted.

Accordingly, the operator can view moving-picture image information withan emphasis on scenes in which persons are imaged.

FIG. 24 is a block diagram of a seventh illustrative implementation ofthe invention (corresponding to FIG. 8).

In FIG. 24, a camera part 51 a is attached to the side surface of themain body of an electronic camera 51, and an imaging lens 52 whichfocuses an image of the object of imaging is mounted in this camera part51 a.

The optical axis of the imaging lens 52 is bent within the camera part51 a, and the light-receiving surface of an imaging element 53consisting of a CCD image sensor, etc., is installed on an extension ofthis optical axis.

The photoelectric output of the imaging element 53 is input via an A/Dconversion part 54 into a video signal processing part 55 which performsa white balance adjustment and gamma correction, etc.

The output of the video signal processing part 55 is input into an imagecompression and expansion part 56 located within the main body; thisimage compression and expansion part 56 is connected with amicro-processor 58 via a system bus 57.

A memory 59, an audio D/A conversion part 60, a disk drive part 61, adisplay memory 62 and a focus control part 65 are connected to theabove-mentioned system bus 57.

The output of the above-mentioned audio D/A conversion part 60 is inputinto a speaker 60 b via an audio amplifier 60 a.

Furthermore, an optical-magnetic recording medium 61 a is mounted in afreely detachable manner in the disk drive part 61.

The display memory 62 is connected to a liquid crystal display part 64via a liquid crystal driving circuit 63.

A focal point detection part 66 which detects the focal point adjustmentconditions of the imaging lens 52, and a lens position detection part 68which detects the lens position of the imaging lens 52, are connected tothe input terminals of the focus control part 65. Furthermore, a focuscontrol motor 69 which moves the imaging lens forward and backward isconnected to the output terminal of the focus control part 65.

The focus control part 65 controls the focus by driving the focuscontrol motor 69 in accordance with the amount of defocusing acquiredfrom the focal point detection part 66.

A record button 51 b, a playback button 51 c and an extraction modeselection dial 51 d are installed in the housing of the electroniccamera 51, and the outputs of these operating parts are respectivelyinput into the micro-processor 58.

Furthermore, in regard to the correspondence between the invention shownin FIG. 8 and the seventh illustrative implementation of the inventionshown in FIG. 24, the imaging means 16 corresponds to the imagingelement 53, the imaging parameter detection means 17 corresponds to thefocal point detection part 66 and lens position detection part 68, themedium recording means 18 corresponds to the disk drive part 61, thetime period discriminating means 19 corresponds to the micro-processor58, the medium playback means 1 corresponds to the disk drive part 61,and the playback display means 3 corresponds to the image compressionand expansion part 56, display memory 62, liquid crystal driving circuit63 and the micro-processor 58.

The operation of the seventh illustrative implementation of theinvention will be described with reference to FIGS. 24 through 26.

(Image Recording Operation)

First, when the main power supply is switched on, the electronic camera51 enters a waiting state until the playback button 51 c or recordbutton 51 b is switched on.

When the playback button 51 c is switched on (FIG. 25 S1) in this state,the micro-processor 58 performs the operation indicated in FIG. 26 S9(which will be described later).

When the record button 51 b is switched on (FIG. 25 S2), themicro-processor 58 instructs the image compression and expansion part 56to begin image compression. The image compression and expansion part 56inputs moving-picture image information from the video signal processingpart 55, and performs image compression processing according to the MPEGstandard (FIG. 25 S3).

In parallel with such image compression, the micro-processor 58 inputsthe lens position and amount of defocusing of the imaging lens 52 viathe focus control part 65 (FIG. 25 S4 and S5).

The disk drive part 61 records the above-mentioned moving-picture imageinformation, lens position and amount of defocusing together in imagefiles on the optical-magnetic recording medium 61 a (FIG. 25 S6).

In this state, the micro-processor 58 returns to FIG. 25 S3, and theabove-mentioned recording operation is repeated (NO side of FIG. 25 S7)until the record button 51 b is pressed again.

When the record button 51 b is pressed again (YES side of FIG. 25 S7),the micro-processor 58 returns to FIG. 25 S1 after performing finalprocessing such as the addition of control data (e.g., date and timedata, etc.) to the image file in preparation (FIG. 25 S8), so that therecording operation is completed.

(Playback Operation)

When the playback button 51 c is switched on (FIG. 25 S1) in theabove-mentioned waiting state, the micro-processor 58 instructs the diskdrive part 61 to read out image files. The disk drive part 61 reads outimage files from the optical-magnetic recording medium 61 a, andsuccessively stores these files in the memory 59 (FIG. 26 S9).

Next, the micro-processor 58 inputs the dial state of the extractionmode selection dial 51 d (FIG. 26 S10), and performs the followingoperations in accordance with this dial state (FIG. 26 S11).

First, in cases where the dial state is “infinitely distant end deletionmode”, the micro-processor 58 inputs the lens position information fromthe image files in the memory 59 in playback order (FIG. 26 S12). Here,moving-picture image information which is synchronized with the lensposition information is played back and displayed (FIG. 26 S14) only incases where the lens position is not at the infinitely distant end (FIG.26 S13).

Furthermore, in cases where the dial state is “point-blank end deletionmode”, the micro-processor 58 inputs the lens position information fromthe image files in the memory 59 in playback order (FIG. 26 S15). Here,moving-picture image information which is synchronized with the lensposition information is played back and displayed (FIG. 26 S17) only incases where the lens position is not at the point-blank end (FIG. 26S16).

Moreover, in cases where the dial state is “out-of-focus deletion mode”,the micro-processor 58 inputs information indicating the amount ofdefocusing from the image files in the memory 59 in playback order (FIG.26 S18). Here, moving-picture image information which is synchronizedwith the lens position information is played back and displayed (FIG. 26S20) only in cases where the amount of defocusing is within the“focused” range (FIG. 26 S19).

In cases where the playback of moving-picture image information is notcompleted after the above series of operations has been completed (NOside of FIG. 26 S21), the operation returns to the processing of FIG. 26S10, and the above operations are repeated.

On the other hand, when the playback of moving-picture image informationis completed (YES side of FIG. 26 S21), the image file playbackoperation is completed.

As a result of the above operations, image files are selectively playedback and displayed in accordance with the conditions of the imaging lens52 at the time of imaging. Accordingly, the operator can appropriatelyextract and view playback scenes in accordance with the conditions ofthe imaging lens 52.

FIG. 27 is a block diagram of a seventh illustrative implementation ofthe invention (corresponding to FIGS. 9 and 10).

In FIG. 27, a camera part 71 a is attached to the side surface of themain body of an electronic camera 71, and an imaging lens 72 whichfocuses an image of the object is mounted in this camera part 71 a.

The optical axis of the imaging lens 72 is bent within the camera part71 a, and the light-receiving surface of an imaging element 73consisting of a CCD image sensor, etc., is installed on an extension ofthis optical axis.

The photoelectric output of the imaging element 73 is input via an A/Dconversion part 74 into a video signal processing part 75 which performsa white balance adjustment and gamma correction, etc.

The output of the video signal processing part 75 is input into an imagecompression and expansion part 76 located within the main body; thisimage compression and expansion part 76 is connected with amicro-processor 78 via a system bus 77.

A memory 79, an audio D/A conversion part 80, a disk drive part 81, adisplay memory 82 and an imaging object temperature detection part 85are connected to the above-mentioned system bus 77.

The output of the above-mentioned audio D/A conversion part 80 is inputinto a speaker 80 b via an audio amplifier 80 a.

Furthermore, an optical-magnetic recording medium 81 a is mounted in afreely detachable manner in the disk drive part 81.

The display memory 82 is connected to a liquid crystal display part 84via a liquid crystal driving circuit 83.

An infrared imaging element 87 equipped with an infrared optical system86 is connected to the input terminal of the imaging object temperaturedetection part 85. Furthermore, an infrared imaging element of thethermal type or quantum type, etc., is used as the above-mentionedinfrared imaging element 87.

A record button 71 b and a playback button 71 c are installed in thehousing of the electronic camera 71, and the outputs of these operatingparts are input into the micro-processor 78.

Furthermore, in regard to the correspondence between the inventionsshown in FIGS. 9 and 10 and the eighth illustrative implementation shownin FIG. 27, the imaging means 16 corresponds to the imaging element 73,the environmental parameter detection means 20 corresponds to theinfrared optical system 86, infrared imaging element 87 and imagingobject temperature detection part 85, the medium recording means 18corresponds to the disk drive part 81, the time period discriminatingmeans 21 corresponds to the micro-processor 78, the medium playbackmeans 1 corresponds to the disk drive part 81, and the playback displaymeans 3 corresponds to the image compression and expansion part 76,display memory 82, liquid crystal driving circuit 83 and themicro-processor 78.

The operation of the eighth illustrative implementation of the inventionwill be described with reference to FIGS. 27 and 28.

(Image Recording Operation)

First, when the main power supply is switched on, the electronic camera71 enters a waiting state until the playback button 71 c or recordbutton 71 b is switched on.

When the playback button 71 c is switched on (FIG. 28 S1) in this state,the micro-processor 78 performs the operation indicated in FIG. 26 S8(which will be described later).

When the record button 71 b is switched on (FIG. 28 S2), themicro-processor 78 instructs the image compression and expansion part 76to begin image compression. The image compression and expansion part 76inputs moving-picture image information from the video signal processingpart 75, and performs image compression processing according to the MPEGstandard (FIG. 28 S3).

In parallel with such image compression, the micro-processor 78instructs the imaging object temperature detection part 85 to detect thetemperature of the object. The object temperature detection part 85detects infrared radiation from the image field via the infrared imagingelement 87, and determines the temperature of the object of (FIG. 28S4).

The disk drive part 81 records the above-mentioned moving-picture imageinformation and object temperature together in image files on theoptical-magnetic recording medium 81 a (FIG. 28 S5).

In this state, the micro-processor 78 returns to FIG. 28 S3, and theabove-mentioned recording operation is repeated (NO side of FIG. 28 S6)until the record button 71 b is pressed again.

When the record button 71 b is pressed again (YES side of FIG. 28 S6),the micro-processor 78 returns to FIG. 28 S1 after performing finalprocessing such as the addition of control data (e.g., date and timedata, etc.) to the image file in preparation (FIG. 28 S7), so that therecording operation is completed.

(Playback Operation)

When the playback button 71 c is switched on (FIG. 28 S1) in theabove-mentioned waiting state, the micro-processor 78 instructs the diskdrive part 81 to read out image files. The disk drive part 81 reads outimage files from the optical-magnetic recording medium 81 a, andsuccessively stores these files in the memory 79 (FIG. 28 S8).

Next, the micro-processor 78 inputs object temperature information fromthe image files in the memory 79 in playback order (FIG. 28 S9).

Here, the micro-processor 78 ascertains whether or not the temperatureof the object is in the range of 30 to 40° C., which is the bodytemperature range of a human being (FIG. 28 S10).

In cases where the temperature of the object is in the above-mentionedbody temperature range (YES side of FIG. 28 S10), the micro-processor 78instructs the image compression and expansion part 76 to perform imageexpansion. The image compression and expansion part 76 inputsmoving-picture image information synchronized with imaging objecttemperature information from the image files in the memory 79, performsimage expansion on this moving-picture image information, and recordsthe resulting image information in the display memory 82. The liquidcrystal driving circuit 83 inputs the moving-picture image informationfrom the display memory 82 in order, and displays this image informationon the liquid crystal display part 84 (FIG. 28 S11).

In cases where the temperature of the object is outside theabove-mentioned body temperature range (NO side of FIG. 28 S10),playback and display are not performed as described above.

In cases where the playback of moving-picture image information is notcompleted after the above series of operations has been completed (NOside of FIG. 28 S12), the operation returns to the processing of FIG. 28S9, and the above operations are repeated.

On the other hand, when the playback of moving-picture image informationis completed (YES side of FIG. 28 S12), the image file playbackoperation is completed.

As a result of the above operations, image files are selectively playedback and displayed only in cases where the temperature of the object isin the human body temperature range. Accordingly, the operator can viewmoving-picture image information with an emphasis on scenes in whichhuman beings are imaged.

In the illustrative implementation of the inventions described above,periods meeting certain conditions were discriminated, and imageinformation was played back and displayed only during these periods.However, the present invention is not limited to such a construction; itwould also be possible to perform such playback and display only duringtime periods other than the discriminated periods.

In the illustrative implementation of the inventions described above,only cases in which partial playback was performed automatically weredescribed in order to simplify the description. However, the presentinvention is not limited to such a construction; for example, it wouldalso be possible for the operator to determine whether or not partialplayback is performed by operating a switch, etc.

In the illustrative implementation of the inventions other than theseventh illustrative implementation of the invention, periods werediscriminated based on a single condition. However, the presentinvention is not limited to such a construction; for example, it wouldalso be possible to install discriminating means for a plurality ofconditions beforehand, with the operator selecting desired conditions byoperating switches, etc. Also, it would also be possible to setprescribed logical operations (logical products, logical sums, etc.) fora plurality of conditions, and to discriminate periods based oncomposite conditions answering to these logical operations. For example,in a case where periods are discriminated based on the logical productof panning discrimination and absence-of-persons discrimination,moving-picture image information can be played back and displayed withan emphasis on “car window scenery with persons absent”, etc.Furthermore, fuzzy logic, etc., can also be employed in such logicaloperations.

In the illustrative implementation of the inventions described above, anoptical-magnetic recording medium was used as the recording medium;however, the present invention is not restricted in terms of the form ormaterial of the recording medium used. For example, semiconductorrecording media, magnetic recording media or optical recording media,etc., may also be used as recording media.

In the second illustrative implementation of the invention, long-termspectrum averages were used as audio characteristic feature parameters;however, the present invention is not limited to such a construction.Any waveform or value which indicates characteristic features of voices,e.g., mean pitch frequency, etc., may be used as a characteristicfeature parameter.

While preferred embodiments and implementations of the invention havebeen shown and described, it will be apparent to those skilled in theart that changes can be made in these embodiments and implementationswithout departing from the principles and spirit of the invention, thescope of which is defined in the appended claims.

1. An image playback device comprising: a medium playback means whichreads out recorded information that has been recorded on a recordingmedium; a time period discriminating means which receives the recordedinformation read out by the medium playback means and discriminatesperiods of time during which the recorded information agrees with atleast one pre-set condition; and a playback display means which playsback and displays moving-picture image information contained in therecorded information in accordance with the results of thediscrimination performed by the time period discriminating means,wherein the time period discriminating means includes: a flesh tonedetection means which receives moving-picture image information from therecorded information read out by the medium playback means, and detectsflesh tone regions within an image screen; and an absence-of-personsdiscriminating means which discriminates periods of absence of personsin which the flesh tone regions detected by the flesh tone detectionmeans drop below a prescribed area; and wherein the playback displaymeans acquires the periods of absence of persons discriminated by theabsence-of-persons discriminating means, and plays back and displaysmoving-picture image information contained in the recorded informationonly during time periods of absence of persons or during time periodsother than time periods of absence of persons.
 2. An image playbackmethod comprising: reading out recorded information that has beenrecorded on a recording medium; discriminating time periods during whichthe read out recorded information agrees with at least one pre-setcondition; and playing back and displaying moving-picture imageinformation contained in the recorded information in accordance with theresults of the discriminating, wherein the time period discriminatingincludes: receiving moving-picture image information from the recordedinformation read out, and detecting flesh tone regions within an imagescreen; and discriminating periods of absence of persons in which thedetected flesh tone regions drop below a prescribed area; and whereinmoving-picture image information contained in the recorded informationis played back and displayed only during discriminated periods ofabsence of persons or during periods other than discriminated periods ofabsence of persons.